Potential consequences of widespread antepartal use of ampicillin

• Published in: American journal of obstetrics and gynecology 1998-10, Vol.179 (4), p.879-883
• Main Authors: Towers, Craig V., Carr, Margaret H., Padilla, Guadalupe, Asrat, Tamerou
• Format: Article
• Language: English
• Subjects: Ampicillin - administration & dosage; Ampicillin - therapeutic use; Ampicillin Resistance; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacteria resistant to ampicillin; Bacterial Infections - epidemiology; Bacterial Infections - prevention & control; Biological and medical sciences; Cohort Studies; complications of antibiotic therapy; early-onset neonatal bacterial sepsis; Escherichia coli Infections - epidemiology; Female; Fetal Membranes, Premature Rupture; Gestational Age; group B streptococci; Humans; Infant, Newborn; Infant, Premature; Medical sciences; Obstetric Labor, Premature; Penicillins - administration & dosage; Penicillins - therapeutic use; Pharmacology. Drug treatments; Pregnancy; Prospective Studies; Sepsis - epidemiology; Sepsis - microbiology; Streptococcal Infections - prevention & control; Streptococcus agalactiae - isolation & purification
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/S0002-9378(98)70182-6

Objective: Recommendations for the use of antenatal antibiotics in obstetrics have increased in the past few years, especially for prophylaxis against group B streptococci, for prolongation of the latency time in patients with preterm premature rupture of the membranes, and as an adjuvant treatment in preterm labor. Our objective was to determine whether the use of antenatal ampicillin affects the incidence of and resistance of early-onset neonatal sepsis with organisms other than group B streptococci. Study Design: A prospective cohort study was performed between January 1, 1991, and December 31, 1996. Every case of blood culture–proven neonatal sepsis was prospectively surveyed. The type of bacteria isolated, drug resistance, antenatal antibiotic use and treatment indication, gestational age at delivery, and other antenatal and outcome variables were gathered. Early-onset neonatal sepsis was defined as disease onset within 7 days after birth. Results: A total of 42 cases of early-onset neonatal sepsis among 29,897 neonates delivered were found during the 6-year period. Of these, 15 cases were due to group B streptococci and 27 were the result of non–group B streptococcal organisms (21 gram-negative rods and 6 gram-positive cocci). Among the 27 non–group B streptococcal cases, 15 mothers had received antenatal ampicillin and 13 of the 15 bacterial isolates from these neonates (87%) were resistant to ampicillin, versus only 2 ampicillin-resistant isolates (17%) among the 12 cases in which no antenatal antibiotics were administered (P = .0004). Of the 15 mothers who were treated with ampicillin, 13 received more than 1 dose. In evaluating each year of the study, the overall administration of antibiotics to pregnant women in the antenatal period increased from